One vertex per element, one color per generator, with an edge from x to x·s.
(3,7)(5,8)(9,10)(11,15)(12,21)(13,23)(14,16)(17,18)(19,24)(20,22)(25,26,31,35)(27,34,29,32)(28,33,39,30)(36,38,37,40)(1,2,4,6)(3,5,7,8)(9,11,14,18)(10,15,16,17)(12,19,23,22)(13,20,21,24)(25,27)(26,32)(28,36)(29,31)(30,38)(33,40)(34,35)(37,39)(1,3)(2,5)(4,7)(6,8)(10,16)(11,18)(13,21)(19,22)(25,28,31,39)(26,33,35,30)(27,36,29,37)(32,40,34,38)(9,11)(10,17)(12,22)(13,20)(14,18)(15,16)(19,23)(21,24)(25,28)(26,33)(27,37)(29,36)(30,35)(31,39)(32,38)(34,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,12)(10,13)(11,19)(14,23)(15,20)(16,21)(17,24)(18,22)(25,29,31,27)(26,34,35,32)(28,37,39,36)(30,40,33,38)(1,3)(2,5)(4,7)(6,8)(9,13)(10,12)(11,20)(14,21)(15,19)(16,23)(17,22)(18,24)(25,30,31,33)(26,28,35,39)(27,38,29,40)(32,36,34,37)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.